关于使用fs.readdir进行异步目录搜索有什么想法吗?我意识到我们可以引入递归,并调用read目录函数来读取下一个目录,但我有点担心它不是异步的…

什么好主意吗?我已经看了node-walk,它很棒,但它不能像readdir那样只给我数组中的文件。虽然

寻找这样的输出…

['file1.txt', 'file2.txt', 'dir/file3.txt']

当前回答

异步

const fs = require('fs')
const path = require('path')

const readdir = (p, done, a = [], i = 0) => fs.readdir(p, (e, d = []) =>
  d.map(f => readdir(a[a.push(path.join(p, f)) - 1], () =>
    ++i == d.length && done(a), a)).length || done(a))

readdir(__dirname, console.log)

Sync

const fs = require('fs')
const path = require('path')

const readdirSync = (p, a = []) => {
  if (fs.statSync(p).isDirectory())
    fs.readdirSync(p).map(f => readdirSync(a[a.push(path.join(p, f)) - 1], a))
  return a
}

console.log(readdirSync(__dirname))

异步读

function readdir (currentPath, done, allFiles = [], i = 0) {
  fs.readdir(currentPath, function (e, directoryFiles = []) {
    if (!directoryFiles.length)
      return done(allFiles)
    directoryFiles.map(function (file) {
      var joinedPath = path.join(currentPath, file)
      allFiles.push(joinedPath)
      readdir(joinedPath, function () {
        i = i + 1
        if (i == directoryFiles.length)
          done(allFiles)}
      , allFiles)
    })
  })
}

readdir(__dirname, console.log)

注意:两个版本都将跟随符号链接(与原始fs.readdir相同)

其他回答

这是另一个实现。上述解决方案都没有任何限制,因此如果您的目录结构很大,它们都会崩溃并最终耗尽资源。

var async = require('async');
var fs = require('fs');
var resolve = require('path').resolve;

var scan = function(path, concurrency, callback) {
    var list = [];

    var walker = async.queue(function(path, callback) {
        fs.stat(path, function(err, stats) {
            if (err) {
                return callback(err);
            } else {
                if (stats.isDirectory()) {
                    fs.readdir(path, function(err, files) {
                        if (err) {
                            callback(err);
                        } else {
                            for (var i = 0; i < files.length; i++) {
                                walker.push(resolve(path, files[i]));
                            }
                            callback();
                        }
                    });
                } else {
                    list.push(path);
                    callback();
                }
            }
        });
    }, concurrency);

    walker.push(path);

    walker.drain = function() {
        callback(list);
    }
};

使用50的并发工作得非常好,并且几乎和小型目录结构的简单实现一样快。

使用async/await,这应该工作:

const FS = require('fs');
const readDir = promisify(FS.readdir);
const fileStat = promisify(FS.stat);

async function getFiles(dir) {
    let files = await readDir(dir);

    let result = files.map(file => {
        let path = Path.join(dir,file);
        return fileStat(path).then(stat => stat.isDirectory() ? getFiles(path) : path);
    });

    return flatten(await Promise.all(result));
}

function flatten(arr) {
    return Array.prototype.concat(...arr);
}

你可以用蓝鸟。许诺或许诺:

/**
 * Returns a function that will wrap the given `nodeFunction`. Instead of taking a callback, the returned function will return a promise whose fate is decided by the callback behavior of the given node function. The node function should conform to node.js convention of accepting a callback as last argument and calling that callback with error as the first argument and success value on the second argument.
 *
 * @param {Function} nodeFunction
 * @returns {Function}
 */
module.exports = function promisify(nodeFunction) {
    return function(...args) {
        return new Promise((resolve, reject) => {
            nodeFunction.call(this, ...args, (err, data) => {
                if(err) {
                    reject(err);
                } else {
                    resolve(data);
                }
            })
        });
    };
};

Node 8+内置了Promisify

请参阅我对生成器方法的其他回答,它可以更快地得到结果。

我建议使用node-glob来完成这个任务。

var glob = require( 'glob' );  

glob( 'dirname/**/*.js', function( err, files ) {
  console.log( files );
});

使用承诺(Q)以函数式风格解决此问题:

var fs = require('fs'),
    fsPath = require('path'),
    Q = require('q');

var walk = function (dir) {
  return Q.ninvoke(fs, 'readdir', dir).then(function (files) {

    return Q.all(files.map(function (file) {

      file = fsPath.join(dir, file);
      return Q.ninvoke(fs, 'lstat', file).then(function (stat) {

        if (stat.isDirectory()) {
          return walk(file);
        } else {
          return [file];
        }
      });
    }));
  }).then(function (files) {
    return files.reduce(function (pre, cur) {
      return pre.concat(cur);
    });
  });
};

它返回一个数组的promise,所以你可以这样使用它:

walk('/home/mypath').then(function (files) { console.log(files); });

为了以防有人发现它有用,我还整理了一个同步版本。

var walk = function(dir) {
    var results = [];
    var list = fs.readdirSync(dir);
    list.forEach(function(file) {
        file = dir + '/' + file;
        var stat = fs.statSync(file);
        if (stat && stat.isDirectory()) { 
            /* Recurse into a subdirectory */
            results = results.concat(walk(file));
        } else { 
            /* Is a file */
            results.push(file);
        }
    });
    return results;
}

提示:在筛选时使用更少的资源。这个函数本身的过滤器。例如:替换results.push(文件);下面的代码。根据需要调整:

    file_type = file.split(".").pop();
    file_name = file.split(/(\\|\/)/g).pop();
    if (file_type == "json") results.push(file);